It's a neat little round. I wouldn't use one today just because the economics favor handloaded 223.
Back in 1978 this muley fell to a 5mm Rimfire Magnum in eastern MT. 36gr JSP bullet at about 2300 fps MV. Deer was hit broadside behind elbow from about 100 yards. He humped up, laid down, and was dead when we got up to him. Didn't intend to use that chambering for deer, but we were out shooting jackrabbits during deer season, and well, stuff happens.
As I recall the bullet entered between two ribs penetrated heart/lungs and stopped between two ribs on the offside.